Kinematics of red cell aspiration by fluorescence-imaged microdeformation
Kinematics of red cell aspiration by fluorescence-imaged microdeformation
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DOI：
10.1016/s0006-3495(96)79424-9
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发表时间：
1996-10-01
影响因子：
3.4
通讯作者：
Mohandas, N
中科院分区：
文献类型：
--
作者：
Discher, DE;Mohandas, N
对移液器抽吸投影上的荧光红细胞膜成分图进行定量，以努力阐明和统一变形的异质运动学。扩散荧光脂质的瞬态梯度首先证明了均匀密度双层的流动性，并证实了相对表面密度的“通用”校准尺度。骨架成分血影蛋白、肌动蛋白和蛋白质 4.1 的密度陡峭但平滑且稳定的梯度用于估计沿吸气骨架的大弹性应变。变形场被认为是对表面法线方向载荷的不受阻碍的响应。特定跨膜蛋白（例如，带 3）显示可压缩骨架和流体双层的中间密度图，以及骨架连接部分的产量估计。这种连接的蛋白质似乎占据了未变形膜表面的很大一部分，并且可以导致未连接的完整膜蛋白质从网络凝聚区域中空间排除。与可逆变形中的膜重新图案化运动学一致，突出尖端的最终囊泡化产生集中于自由扩散的蛋白质但骨架耗尽的细胞碎片。
Maps of fluorescing red cell membrane components on a pipette-aspirated projection are quantitated in an effort to elucidate and unify the heterogeneous kinematics of deformation. Transient gradients of diffusing fluorescent lipid first demonstrate the fluidity of an otherwise uniform-density bilayer and corroborate a ''universal'' calibration scale for relative surface density. A steep but smooth and stable gradient in the densities of the skeleton components spectrin, actin, and protein 4.1 is used to estimate large elastic strains along the aspirated skeleton. The deformation fields are argued to be an unhindered response to loading in the surface normal direction. Density maps intermediate to those of the compressible skeleton and fluid bilayer are exhibited by particular transmembrane proteins (e.g., Band 3) and yield estimates for the skeleton-connected fractions. Such connected proteins appear to occupy a significant proportion of the undeformed membrane surface and can lead to steric exclusion of unconnected integral membrane proteins from regions of network condensation. Consistent with membrane repatterning kinematics in reversible deformation, final vesiculation of the projection tip produces a cell fragment concentrated in freely diffusing proteins but depleted of skeleton.